I don't think mthfr testing is common in Australia. The genes have only recently been identified. Often they'll test homosycteine (sp) levels, as elevated levels can indicate a mthfr mutation. However, apparently they can be normal and still have a mthfr mutation.

There are also a multitude of individual genes which your could both be carriers for. Unfortunately, unless they know what to look for, they can't often find it. It may be worth having a micro array done. It's a panel of extended chromosomal/genetic tests they do in addition to standard counting the chromosomes (karotyping).

And as my genetic counsellor pointed out, genetic testing isn't 100% accurate. Sometimes they find things, sometimes they don't. Even with standard tests like cystic fibrosis carrier status, they've only identified 12 possible mutations out of how many unknown ones. But it's better than doing nothing and they're discovering new things all the time.

Have you ever had the babies tested after a miscarriage? Sometimes they can find things, depending on gestation and time since death.

Another things is it is apparently possible to develop an immune response to embryos. I don't know what that's called or if they can test for it, but worth asking about.